Many ophthalmic devices, including contact lenses, surgical lenses, intraocular lenses, and the like, are often made by performing a polymerization reaction within a casting cup assembly. The casting cup assembly includes a basecurve mold, which forms the portion of the device that rests against the eye, and a frontcurve mold, which forms the portion of the device facing away from the eye. A reaction mixture, which includes one or more polymerizable monomers and other components, is disposed in the frontcurve mold. Thereafter, the basecurve mold is pressed against the frontcurve mold and the reaction mixture is forced to adopt the shape of the volume defined between the two molds. After properly being positioned, the reaction mixture is subjected to polymerization conditions (e.g. photopolymerization or other suitable technique). The resulting polymer is removed from the casting cup assembly and subjected to post-polymerization processing (e.g. rinsing, hydration, etc) to provide a finished ophthalmic device. During this post-polymerization processing, careful inspection of the lenses often reveals a substantial number of the lenses contain defects.
Defects include a variety of fabrication errors such as holes in the lenses, tears in the edges, the presence rings of excess polymer around the ophthalmic device, and other similar defects. Therefore, an improved method for providing ophthalmic devices is desired that reduces the occurrence of these defects.